feat(chat): add Slack integration with channel resolution and tools (#23)

Author: qasim-nylas

internal/chat/approval.go

@@ -11,8 +11,9 @@ const approvalTimeout = 5 * time.Minute
 
 // gatedTools lists tools that require user approval before execution.
 var gatedTools = map[string]bool{
-	"send_email":   true,
-	"create_event": true,
+	"send_email":         true,
+	"create_event":       true,
+	"send_slack_message": true,
 }
 
 // IsGated returns true if the tool requires user approval.
@@ -133,6 +134,19 @@ func BuildPreview(call ToolCall) map[string]any {
 		if desc, ok := call.Args["description"].(string); ok {
 			preview["description"] = desc
 		}
+	case "send_slack_message":
+		if ch, ok := call.Args["channel"].(string); ok {
+			preview["channel"] = ch
+		}
+		if text, ok := call.Args["text"].(string); ok {
+			if len(text) > 200 {
+				text = text[:200] + "..."
+			}
+			preview["text"] = text
+		}
+		if threadTS, ok := call.Args["thread_ts"].(string); ok && threadTS != "" {
+			preview["thread_ts"] = threadTS
+		}
 	}
 
 	return preview

internal/chat/approval_test.go

@@ -1,6 +1,7 @@
 package chat
 
 import (
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -201,6 +202,31 @@ func TestPendingApproval_WaitConcurrent(t *testing.T) {
 	wg.Wait()
 }
 
+func TestIsGated_SlackMessage(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name     string
+		toolName string
+		want     bool
+	}{
+		{"send_slack_message is gated", "send_slack_message", true},
+		{"list_slack_channels is not gated", "list_slack_channels", false},
+		{"read_slack_messages is not gated", "read_slack_messages", false},
+		{"search_slack is not gated", "search_slack", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got := IsGated(tt.toolName)
+			if got != tt.want {
+				t.Errorf("IsGated(%q) = %v, want %v", tt.toolName, got, tt.want)
+			}
+		})
+	}
+}
+
 func TestBuildPreview(t *testing.T) {
 	t.Parallel()
 
@@ -292,3 +318,50 @@ func TestBuildPreview(t *testing.T) {
 		})
 	}
 }
+
+func TestBuildPreview_SlackMessage(t *testing.T) {
+	t.Parallel()
+
+	preview := BuildPreview(ToolCall{
+		Name: "send_slack_message",
+		Args: map[string]any{
+			"channel":   "#engineering",
+			"text":      "Hello team!",
+			"thread_ts": "1234567890.123456",
+		},
+	})
+
+	if preview["channel"] != "#engineering" {
+		t.Errorf("channel = %v, want %q", preview["channel"], "#engineering")
+	}
+	if preview["text"] != "Hello team!" {
+		t.Errorf("text = %v, want %q", preview["text"], "Hello team!")
+	}
+	if preview["thread_ts"] != "1234567890.123456" {
+		t.Errorf("thread_ts = %v, want %q", preview["thread_ts"], "1234567890.123456")
+	}
+}
+
+func TestBuildPreview_SlackMessage_LongText(t *testing.T) {
+	t.Parallel()
+
+	longText := strings.Repeat("a", 300)
+	preview := BuildPreview(ToolCall{
+		Name: "send_slack_message",
+		Args: map[string]any{
+			"channel": "#general",
+			"text":    longText,
+		},
+	})
+
+	text, ok := preview["text"].(string)
+	if !ok {
+		t.Fatal("text is not a string")
+	}
+	if len(text) > 203 { // 200 + "..."
+		t.Errorf("text length = %d, want <= 203", len(text))
+	}
+	if !strings.HasSuffix(text, "...") {
+		t.Error("text should end with '...'")
+	}
+}

internal/chat/chat.go

@@ -9,9 +9,36 @@ import (
 
 	browserpkg "github.com/nylas/cli/internal/adapters/browser"
 	"github.com/nylas/cli/internal/adapters/config"
+	"github.com/nylas/cli/internal/adapters/keyring"
+	slackadapter "github.com/nylas/cli/internal/adapters/slack"
 	"github.com/nylas/cli/internal/cli/common"
+	"github.com/nylas/cli/internal/ports"
 )
 
+// trySlackClient attempts to create a Slack client from stored credentials.
+// Returns nil if Slack is not configured (not an error).
+func trySlackClient() ports.SlackClient {
+	token := os.Getenv("SLACK_USER_TOKEN")
+	if token == "" {
+		store, err := keyring.NewSecretStore(config.DefaultConfigDir())
+		if err != nil {
+			return nil
+		}
+		token, err = store.Get("slack_user_token")
+		if err != nil || token == "" {
+			return nil
+		}
+	}
+
+	cfg := slackadapter.DefaultConfig()
+	cfg.UserToken = token
+	client, err := slackadapter.NewClient(cfg)
+	if err != nil {
+		return nil
+	}
+	return client
+}
+
 // NewChatCmd creates the chat command.
 func NewChatCmd() *cobra.Command {
 	var (
@@ -73,6 +100,8 @@ and perform actions on your behalf through a web-based chat interface.`,
 				return err
 			}
 
+			slackClient := trySlackClient()
+
 			// Set up conversation storage
 			chatDir := filepath.Join(config.DefaultConfigDir(), "chat", "conversations")
 			memory, err := NewMemoryStore(chatDir)
@@ -85,6 +114,9 @@ and perform actions on your behalf through a web-based chat interface.`,
 
 			fmt.Printf("Starting Nylas Chat at %s\n", url)
 			fmt.Printf("Agent: %s\n", agent)
+			if slackClient != nil {
+				fmt.Println("Slack: connected")
+			}
 			fmt.Println("Press Ctrl+C to stop")
 			fmt.Println()
 
@@ -96,7 +128,7 @@ and perform actions on your behalf through a web-based chat interface.`,
 				}
 			}
 
-			server := NewServer(addr, agent, agents, nylasClient, grantID, memory)
+			server := NewServer(addr, agent, agents, nylasClient, grantID, memory, slackClient)
 			return server.Start()
 		},
 	}

internal/chat/context.go

@@ -15,17 +15,19 @@ const (
 
 // ContextBuilder constructs prompts with conversation context and manages compaction.
 type ContextBuilder struct {
-	agent   *Agent
-	memory  *MemoryStore
-	grantID string
+	agent    *Agent
+	memory   *MemoryStore
+	grantID  string
+	hasSlack bool
 }
 
 // NewContextBuilder creates a new ContextBuilder.
-func NewContextBuilder(agent *Agent, memory *MemoryStore, grantID string) *ContextBuilder {
+func NewContextBuilder(agent *Agent, memory *MemoryStore, grantID string, hasSlack bool) *ContextBuilder {
 	return &ContextBuilder{
-		agent:   agent,
-		memory:  memory,
-		grantID: grantID,
+		agent:    agent,
+		memory:   memory,
+		grantID:  grantID,
+		hasSlack: hasSlack,
 	}
 }
 
@@ -38,7 +40,7 @@ func (c *ContextBuilder) BuildPrompt(conv *Conversation, newMessage string) stri
 	var sb strings.Builder
 
 	// System prompt
-	sb.WriteString(BuildSystemPrompt(c.grantID, c.agent.Type))
+	sb.WriteString(BuildSystemPrompt(c.grantID, c.agent.Type, c.hasSlack))
 	sb.WriteString("\n---\n\n")
 
 	// Include conversation summary if available

internal/chat/context_test.go

@@ -12,7 +12,7 @@ func TestContextBuilder_BuildPrompt(t *testing.T) {
 	agent := &Agent{Type: AgentClaude, Path: "/usr/bin/claude"}
 	store := setupMemoryStore(t)
 	grantID := "test-grant-123"
-	builder := NewContextBuilder(agent, store, grantID)
+	builder := NewContextBuilder(agent, store, grantID, false)
 
 	tests := []struct {
 		name       string
@@ -124,7 +124,7 @@ func TestContextBuilder_BuildPrompt(t *testing.T) {
 func TestContextBuilder_NeedsCompaction(t *testing.T) {
 	agent := &Agent{Type: AgentClaude, Path: "/usr/bin/claude"}
 	store := setupMemoryStore(t)
-	builder := NewContextBuilder(agent, store, "test-grant")
+	builder := NewContextBuilder(agent, store, "test-grant", false)
 
 	tests := []struct {
 		name        string
@@ -246,7 +246,7 @@ func TestContextBuilder_NeedsCompaction(t *testing.T) {
 func TestContextBuilder_findSplitIndex(t *testing.T) {
 	agent := &Agent{Type: AgentClaude, Path: "/usr/bin/claude"}
 	store := setupMemoryStore(t)
-	builder := NewContextBuilder(agent, store, "test-grant")
+	builder := NewContextBuilder(agent, store, "test-grant", false)
 
 	tests := []struct {
 		name        string
@@ -372,7 +372,7 @@ func TestContextBuilder_findSplitIndex(t *testing.T) {
 func TestContextBuilder_BuildPrompt_Structure(t *testing.T) {
 	agent := &Agent{Type: AgentClaude, Path: "/usr/bin/claude"}
 	store := setupMemoryStore(t)
-	builder := NewContextBuilder(agent, store, "test-grant")
+	builder := NewContextBuilder(agent, store, "test-grant", false)
 
 	conv := &Conversation{
 		ID:      "conv_test",

internal/chat/executor.go

@@ -12,12 +12,18 @@ import (
 // ToolExecutor dispatches tool calls to the Nylas API.
 type ToolExecutor struct {
 	client  ports.NylasClient
+	slack   ports.SlackClient
 	grantID string
 }
 
 // NewToolExecutor creates a new ToolExecutor.
-func NewToolExecutor(client ports.NylasClient, grantID string) *ToolExecutor {
-	return &ToolExecutor{client: client, grantID: grantID}
+func NewToolExecutor(client ports.NylasClient, grantID string, slack ports.SlackClient) *ToolExecutor {
+	return &ToolExecutor{client: client, grantID: grantID, slack: slack}
+}
+
+// HasSlack returns true if Slack integration is available.
+func (e *ToolExecutor) HasSlack() bool {
+	return e.slack != nil
 }
 
 // Execute runs a tool call and returns the result.
@@ -39,6 +45,19 @@ func (e *ToolExecutor) Execute(ctx context.Context, call ToolCall) ToolResult {
 		return e.listContacts(ctx, call.Args)
 	case "list_folders":
 		return e.listFolders(ctx)
+	// Slack tools
+	case "list_slack_channels":
+		return e.listSlackChannels(ctx, call.Args)
+	case "read_slack_messages":
+		return e.readSlackMessages(ctx, call.Args)
+	case "read_slack_thread":
+		return e.readSlackThread(ctx, call.Args)
+	case "search_slack":
+		return e.searchSlack(ctx, call.Args)
+	case "send_slack_message":
+		return e.sendSlackMessage(ctx, call.Args)
+	case "list_slack_users":
+		return e.listSlackUsers(ctx, call.Args)
 	default:
 		return ToolResult{Name: call.Name, Error: fmt.Sprintf("unknown tool: %s", call.Name)}
 	}
@@ -160,8 +179,8 @@ func (e *ToolExecutor) searchEmails(ctx context.Context, args map[string]any) To
 	}
 
 	params := &domain.MessageQueryParams{
-		Limit:       10,
-		SearchQuery: query,
+		Limit:   10,
+		Subject: query,
 	}
 
 	if v, ok := args["limit"]; ok {